Decorative lamp filament



FIG. 1 is a perspective view of a decorative lamp filament according to the present design;

FIG. 2 is a front view of the decorative lamp filament shown in FIG. 1;

FIG. 3 is a back view of the decorative lamp filament shown in FIG. 1;

FIG. 4 is a first side view of the decorative lamp filament shown in FIG. 1;

FIG. 5 is a second side view of the decorative lamp filament shown in FIG. 1;

FIG. 6 is a top view of the decorative lamp filament shown in FIG. 1; and,

FIG. 7 is a bottom view of the decorative lamp filament shown in FIG. 1.

Applicant respectfully submits that the broken or dashed line format lines shown herein are for illustrative purposes only and form no part of the claimed design. 

CLAIM The ornamental design for a decorative lamp filament, as shown and described. 